The following U.S. patents and U.S. patent applications are incorporated by reference in their entirety:
U.S. Pat. No. 4,050,359 discloses a hydraulic system for a combined power trim and shock absorbing piston-cylinder unit of an outboard motor. The system includes a reversible pump means having a trim-up port connected by a pressure responsive pilot valve piston cylinder unit and a trim-down port through a reverse lock solenoid valve and a down-pilot spool valve providing full drain flow for trim-up and power flow for trim-down. An “up-reverse” pilot valve with a pressure operator is in parallel with the reverse lock valve and provides a restricted by-pass for limited trim-up in reverse. The trim-up hydraulic input or powered side of the cylinder units define a trapped hydraulic system creating “memory” in the system so after impact the motor returns to the original trim position. The return side permits relatively free-flow to permit “trail-out” under low impact. At high speed impact, the flow is restricted and cylinder pressure increases. At a selected point, a shock valve within the piston-cylinder opens and absorbs the shock forces. The piston unit includes an inner floating head telescoped into a head secured to the piston rod with a chamber thereby formed to store the liquid flow during shock movement. A metered orifice and check valve allows return to the original trim-set position.
U.S. Pat. No. 4,872,857 discloses a system for optimizing the operation of a marine drive of the type whose position may be varied with respect to the boat by the operation of separate lift and trim/tilt means. The system includes an automatic control system which stores preselected drive unit positions for various operating modes and is operative to return the drive unit to any pre-established position by pressing a selected operating mode positioning button. The various operating modes may include cruising, acceleration, trolling and trailering position, any of which may be selectively modified to accommodate changes in both operating or environmental conditions. This system may incorporate other optimization routines and/or automatic engine protection systems to provide virtually complete push button operation for complex marine drive unit positioning mechanisms.
U.S. Pat. No. 5,707,263 discloses a system for a trimmable marine stem drive that shifts the trimmable range on a conventional hydraulic trim system. The system includes an enlarged cylinder anchor pin hole in the drive shaft housing, an anchor pin smaller in size than the enlarged anchor pin hole located in the drive shaft housing, and a movable trim adjustment insert that is inserted into the enlarged anchor pin hole to secure the anchor pin in a fixed position within the enlarged hole. It is preferred that the enlarged anchor pin hole be a substantially horizontal elongated hole, and that the trim adjustment insert be placed rearward of the anchor pin to position the anchor pin in a forward position, or forward of the anchor pin to locate the anchor pin in a rearward position. The invention shifts the trimmable range of the drive, while maintaining vibration isolation characteristics available in conventional hydraulic trim systems.
U.S. Pat. No. 6,176,170 discloses a shock absorbing hydraulic actuator comprising a cylinder with first and second pistons slidably disposed therein. The first and second pistons are moveable relative to each other. A poppet is supported by the first piston and is moveable relative to the first piston. In response to hydraulic fluid pressure within a passage of the first piston, the poppet can be caused to move in a direction which opens a passage through the first piston to allow the first piston to move relative to the second piston in response to a shock impact such as that which can result from an outboard motor striking a submerged or floating object. The second piston remains in its original position. A bleed passage allows the first piston to resume its original position next to the second piston after the impact has occurred. This movement towards its original position is caused naturally by the weight of an object supported by the hydraulic actuator, such as an outboard motor.
U.S. Pat. No. 6,183,321 discloses an outboard motor having a pedestal that is attached to a transom of a boat, a motor support platform that is attached to the outboard motor, and a steering mechanism that is attached to both the pedestal and the motor support platform. A hydraulic tilting mechanism is attached to the motor support platform and to the outboard motor. The outboard motor is rotatable about a tilt axis relative to both the pedestal and the motor support platform. A hydraulic pump is connected in fluid communication with the hydraulic tilting mechanism to provide pressurized fluid to cause the outboard motor to rotate about its tilting axis. An electric motor is connected in torque transmitting relation with the hydraulic pump. Both the electric motor and the hydraulic pump are disposed within the steering mechanism.
U.S. Pat. No. 6,273,771 discloses a control system for a marine vessel that incorporates a marine propulsion system that can be attached to a marine vessel and connected in signal communication with a serial communication bus and a controller. A plurality of input devices and output devices are also connected in signal communication with the communication bus and a bus access manager, such as a CAN Kingdom network, is connected in signal communication with the controller to regulate the incorporation of additional devices to the plurality of devices in signal communication with the bus whereby the controller is connected in signal communication with each of the plurality of devices on the communication bus. The input and output devices can each transmit messages to the serial communication bus for receipt by other devices.
U.S. Pat. No. 7,156,709 discloses a calibration procedure that allows an upward maximum limit of tilt to be automatically determined and stored as an operator rotates a marine propulsion device relative to a marine vessel with a particular indication present. That indication can be a grounded circuit point which informs a microprocessor that at calibration procedure is occurring in relation to an upward trim limit. When the ground wire is removed or disconnected from the circuit point, the microprocessor knows that the calibration process is complete. During the rotation of the outboard motor or marine propulsion device in an upward direction, both the angular position of the outboard motor and the direction of change of a signal from a trim sensor are stored.
U.S. Pat. No. 7,942,711 discloses a method for controlling a marine propulsion trim system under two distinct modes of operation. A first mode operates hydraulic cylinders at a slower speed when the associated marine vessel is being operated at a speed above a predetermined threshold. For example, when the marine propulsion device is under load, such as when the marine vessel is operating on plane, the first mode of operation is used and the trim/tilt cylinders are operated at a slower speed. A second mode of operation is used when the marine propulsion system is being operated below a predetermined threshold. In other words, if the marine vessel is operating at a slow speed, the faster mode of operation is used. Similarly, if the marine vessel is being prepared for transport on a trailer, the very slow or non-existent speed of operation of the engine is used as an indicator which causes the second mode of operation to be employed.
U.S. Pat. No. 8,113,892 discloses a marine propulsion control system that receives manually input signals from a steering wheel or trim switches and provides the signals to first, second, and third controllers. The controllers cause first, second, and third actuators to move control devices. The actuators can be hydraulic steering actuators or trim plate actuators. Only one of the plurality of controllers requires connection directly to a sensor or switch that provides a position signal because the controllers transmit signals among themselves. These arrangements allow the various positions of the actuated components to vary from one device to the other as a result of calculated positions based on a single signal provided to one of the controllers.
Unpublished U.S. patent application Ser. No. 14/594,228, filed on Jan. 12, 2015, entitled “Systems and Methods for Controlling Trim Position of a Marine Propulsion Device on a Marine Vessel,” discloses systems and methods for controlling trim position of a marine propulsion device on a marine vessel. The system comprises a trim actuator having a first end that is configured to couple to the marine propulsion device and a second end that is configured to couple to the marine vessel. The trim actuator is movable between an extended position wherein the marine propulsion device is trimmed up with respect to the marine vessel and a retracted position wherein the marine propulsion device is trimmed down with respect to the marine vessel. Increasing an amount of voltage to an electromagnet increases the shear strength of a magnetic fluid in the trim actuator thereby restricting movement of the trim actuator into and out of the extended and retracted positions and wherein decreasing the amount of voltage to the electromagnet decreases the shear strength of the magnetic fluid thereby facilitates movement of the trim actuator into and out of the extended and retracted positions. A controller is configured to adapt the amount of voltage to the electromagnet based upon at least one condition of the system.